DESCRIPTION OF THE PROJECT: TRIAD (Translating Research Into Action for Diabetes) is a long-term, multicenter, prospective observational study of diabetes care in managed care. TRIAD linked survey data from patients, providers, and health plans with chart review information, health plan administrative data, and National Death Index data to establish the largest and richest database of diabetes care ever assembled. TRIAD established productive collaborations that have allowed investigators to address a wide variety of important health service, epidemiological, and clinical questions. We propose to further examine the health system and patient-level factors associated with processes of care, morbidity, mortality, and cost in persons with diabetes. Analyses have been designed to use existing data collected in TRIAD, to have particular relevance to public health and health care reform, and to address quality, outcomes, and costs of care with a special focus on underserved and high-risk populations.